Mars has launched a range of “lower calorie” chocolates bars that are the same price as the standard-sized snacks – but up to 50% smaller.

Classic Mars bars, along with Twix and Snickers, have been reinvented as “100 calories or less” snacks. But they have shrunk the size, with the mini-versions costing the same as original multi-packs.

A 10-pack of slimmed-down 21g Mars bars is listed by Tesco at £2, while nine of its 33.8g snack bars are also £2 – giving 31% less chocolate for the same price.

And 10 reduced-size 20g Twix bars are being offered for £2, compared to nine 40g bars at the same price.

It reignited the row over “shrinkflation” – cutting the size of a product but not the price.

On social media, some critics branded it “a gimmick to increase profit”.

Mars said British customers would rather have a smaller portion than larger low-sugar alternatives.

Snickers and Mars chocolate bars lie on a table
People are not happy about the price

Chocolate fans took to social media to vent their fury.

Callum Mccrae said: “The ever shrinking size of chocolate bars whilst the prices increase.”

Fiona Anderson added: “The price of chocolate and its shrinking size is shocking.”

Others dubbed it “a gimmick to increase profit margin”.

Kate wrote: “Are they just going to keep shrinking chocolate bars until you’ll require a pair of tweezers to pick them up?”

And Jim Rea raged: “Most of these companies are a disgrace with the shrinking size of their products.

“Like Wagon Wheels, Mars bars and just everything else, getting so small, it will be a morsel in years to come, but they will still proudly display ‘Not currently recycled’ on their packaging!”

Mars said consumer research had found British customers would rather have a smaller portion than larger low-sugar alternatives.

Kerry Cavanaugh, Mars Wrigley UK marketing director, said: “If you’re like me and love a sweet treat but are calorie conscious, these chocolate bars are for you.

“Our new 100-calorie range gives people their favourite brands in a smaller size, which is perfect for the 68% of Brits who said recently that they would prefer less of their favourite chocolate than compromise on taste.”

A spokesperson added that all its original line up of bars will still be available, adding the 100-calorie format is an addition to its range, not a replacement.

The hero comes after rival Ferrero last week announced it was slashing the size of Nutella jars without reducing the price.